Piping and Instrumentation Diagrams P&IDs are an integral part for any process company but what are they and how should you read them?

P&ID Symbols


Piping and Instrumentation Diagram, P&IDs, are detailed drawings used in the process industry that depict piping and process equipment, instrumentation and control devices along with safety systems in place that ensure the process remains running in a safe operational state. Applicable to the complete process life cycle, they are first used as part of a detailed design process and in operation, as part of maintenance and asset management. As a routine safety study, P&IDs will further form an essential document in a hazard and operability study (HAZOP).

Originally prepared as hand-drawn and later in CAD formats, these P&IDs are limited to the depiction of processes. The Smart or Intelligent P&ID adds a further valuable attribute in that the depicted assets hold all information relating to that asset, ‘Metadata’. Held within an exportable database, this Metadata can be utilized by both asset maintenance, fiscal financial information for depreciation along with document management systems. The ability to collate data into a single source document will obviously enhance your operation.

Understandably, P&IDs are therefore considered an essential piece of documentation for operators of processes and for many, a statutory and legislative requirement. Were an accident to occur, our safety agencies would expect to review up to date accurately depicting P&IDs at the outset of an accident investigation. Aside from legislative requirements, an up-to-date P&ID enhances operational performance, adding benefits not only to those responsible for process operation but management, maintenance, and in consideration of new project initiatives.

Better access to data equates to improved process insight and the well-maintained Smart P&ID becomes a trusted document, complete with asset information that will, as a result, reduce the number of site visits necessary.

Visit our article on LinkedIn regarding: “Preparing Piping & Instrumentation Diagrams using 3D laser scanning technology”


P&ID Time Saving


True as-built P&IDs provide a time and therefore cost savings to process site by firstly providing their engineering and operational departments access to data to allow them to work more efficiently and secondly to the company to help better understand the assets they have for asset depreciation costs.

Benefits of P&IDs for Safety Image


P&IDs provide considerable safety and efficiency gains by providing process staff the knowledge they need about their site with the need to go out on site.

P&ID Benefit Image for Collaboration


Piping and Instrumentation diagrams have always been looked at as being the bible document of a process site, something which should depict the true as-built nature of the site, so that collaboration between staff, the terminal, contractors, legislative bodies can work together.

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Example of P&ID Station